The present invention relates to bicycles, and more specifically to the mounting arrangement of the pedal cranks for a bicycle which enables the user to propel the bicycle efficiently with less effort.
In a regular bicycle, a bottom bracket bearing axle 11' is revolvably supported in a bottom bracket at the bottom side of the frame 10', a chain wheel 12' is mounted on one end of the bottom bracket bearing axle 11', a chain 14' is mounted on the chain wheel 12' and a sprocket wheel 13', and two pedal assemblies 15' are respectively connected to the ends of the bottom bracket bearing axle 11'. Each pedal assembly 15' comprises a crank 16' and a pedal 17'. This crank mounting arrangement is not satisfactory in function. Because the cranks 16' of the pedal assemblies 15' are respectively fixedly connected to the ends of the bottom bracket bearing axle 11', the arm of force is limited, and the user must employ much effort to the pedals 17' when pedaling the pedal assemblies 15'.